Employees at an online clothing warehouse have accused the company of "putting people's lives at risk" through a lack of social distancing.
Several workers at Clipper Logistics in Ollerton, Nottinghamshire, said warehouse staff were "crammed into corridors" and given no hand sanitiser.
It comes as people have been told to keep at least 2m (6ft 6in) apart to help curb the spread of coronavirus.
Staff have also said their jobs should be classed as "non-essential".
Carly Maddock had worked at Clipper for three years, dealing with clothing refunds for High Street retailers, including M&S and River Island.
She walked out on Wednesday - along with two other colleagues - over the lack of action taken from management.
The mother-of-three said: "It's not good, the corridors are tiny, there's been no hand sanitiser for weeks apart from in the offices.
"We just thought that for everybody's safety they'd just shut it down because we're non-essential, but they didn't."
She said when she questioned the lack of social distancing and hygiene at the warehouse, a manager told her "at this time all I care is about getting refunds processed".
"When I voiced my opinions and said I felt unsafe one manager said 'Just think of how many people die of cancer every year'."
Ms Maddock said anyone who did not turn up to work would either be sacked or go unpaid.
Non-essential shops, including clothing outlets and electronic stores, were ordered to close immediately on 23 March for three weeks, when the measures were due to be reviewed.
One member of staff, who did not want to be named, said hundreds of people continued to sign in using a fingerprint scanner.
He said: "At the workplace there's no social distancing.
"I live with my mum who's got an underlying health condition and is at risk, it is really worrying me.
"I do think they're putting people's lives at risk. There's easily 100 to 200 people in the hallway, all having to press the same security buttons, having to clock out with the same finger scanners.
"I've seen people sneezing into their hands and wiping it on their trousers."
The Health and Safety Executive said although it had no authority to enforce public health measures, "any concerns about the health, wellbeing or safety of workers would be a concern to us".
A spokeswoman for Clipper said circumstances surrounding coronavirus were "evolving on a daily basis" and it was "continuing to monitor and adhere to all government advice".
She said the company had been "inundated with requests" from customers and it was working to support "a wider network of essential services including major food retailers".
An M&S spokesperson said the company "fully supports the government's efforts to protect our NHS and save lives", and had asked customers not to return non-essential items to stores, which would "usually be processed at Clipper".